bad head gasket, fix or motor swap, want to keep manual trans

[Dieselchessy]

I tend to pull the motor if I have to do a head gasket on a high mileage 3.4.
By time you get the heads off all you have left in the rig is the block with AC pump, oil cooler, engine mounts, starter, and bolted to the tranny.

My reasons:

Most often the oil pan seal is leaking. To pull the heads your 3/4 there so I just go all the way.
Most often I want to address the rear main. Might as well.
I've always done both head gaskets. Might as well.

I find it easier to do the work with the engine on a stand. The exhaust manifolds are easier (replacing studs), the oil pan seal is easy, cleaning is easy, ect.....

 

[photoleif]

Am I crazy to think I could do an engine swap in a weekend with help and the right tools?

no, that's not crazy. if you have the donor ready, right tools, FIPG, belts, new water pump... all that, yep you can do that in a weekend. i posted up in a different thread that my mechanic and i pulled a cratered 3.4 and dropped in a dressed long block, in 10 hrs, start to finish. i had done a little removal first on my own. we just kept up the pace, never really stopped doing stuff, and it got done.

do have some help, and if you're not familiar with parts of what you need to do, see [MENTION=120071]mtbtim[/MENTION]'s vids to cure most of that, ha. you'll be happiest if you have an engine crane. we wished i had used a paint pen to mark hoses and stuff first, but it worked out.

 

[MikeGCA1986]

What was the final decision? Engine Swap or just replace the Head Gasket.

My 98 had some overheating issues yesterday. When I took it in today, I was told that the head gasket seems to have a small leak. Just like normal, it was quoted at $1600 but after the heads are machined, $2200. Then the mechanic leads into saying that the bottom end could blow out if the pressure builds up too much after the top end is reworked. From their we went in to discussing a new engine installed at approximation $7000. Has anyone had issues after having the HG replaced?

I hate to jump on your thread for advice, newbie over here can't post his own thread yet...

 

[plcfcng]

What was the final decision? Engine Swap or just replace the Head Gasket.

My 98 had some overheating issues yesterday. When I took it in today, I was told that the head gasket seems to have a small leak. Just like normal, it was quoted at $1600 but after the heads are machined, $2200. Then the mechanic leads into saying that the bottom end could blow out if the pressure builds up too much after the top end is reworked. From their we went in to discussing a new engine installed at approximation $7000. Has anyone had issues after having the HG replaced?

I hate to jump on your thread for advice, newbie over here can't post his own thread yet...

Mike from what I have been told the bottom end are really solid if it has not been abused I would just do the head gaskets after doing a compression test to ensure the rings are in good shape. If you have the HG done then have the heads machined and roll the dice. if you are worried about the bottom end then pull a rod cap and look at the bearing if they look ok then you have all the info you need. I have done 3 HG on the 3.4 1. over 300,000 2. 245,000 3. 175,000 :lever:

 

[mmw0k7o]

My head gasket blew at 235k miles. The overheating that resulted also cracked one of my heads. The job was not terribly difficult. There is a great series of videos on youtube that make the job much easier.

YouTube

I found a nice set of heads at a junk yard that I had resurfaced at a local machine shop. The gasket kit also included a valve cover gasket, so you can check that off your list as well. Don't forget to replace the head bolts, as they're torque to fail.

While the heads are off and all your valves are pulled out you can resurface them if you want to increase your compression. I resurfaced all of mine using Permatex valve grinding compound and saw an impressive increase in compression and power.

 

[rexassian]

$1600-$2000 is great, my quote was $4k-$6k. I chose to just add some stop leak (Blue Devil brand) for now and it's been holding just fine. I am waiting on some insurance auctions to get going and buy a low milage swap.

My biggest issue it letting the project sit too long. If I can knock things out in a weekend, then I know I'll keep this truck going strong. Time is a premium for me. However, I do have a daily driver so I don't mind if I can't use my 4runner right away, I just don't like to plan for a long downtime.

I'm all in favor of a DIY rebuild, I just know myself (and my wife's impatience to not have it sit in the garage for months). I would totally say go for it if you have the time, space, and patience.

 

[plcfcng]

If you need to send the heads out for resurfacing, valve adjustment ect. which has been the case for me on the 3 engines I have done then plan on at least a week. If your not going to keep it very long and did a slam job with all the parts and tools sitting in you lap a long weekend it could be possible.

lIf you have not done one before you need a tool made, borrowed or purchased to deal with these items.

1. Crank pulley holder and maybe a puller too.

2. Camshaft holder

3. A Die to clean up exhaust manifold studs ( I find it helpful )

4. A Torque wrenches for those critical things ( I use them a lot to many years on non aluminium engines to trust not pulling threads out )

I'm sure each person runs into a different problem that just holds them up on each job. :frog: